This invention relates to the use of laser and photon energy for the deposition of reaction products on surfaces, and, more particularly, to an apparatus and process for generating reactive species and then depositing that reactive species.
Laser-induced decomposition of a reactive gas is a well-known approach for depositing a material onto a surface. In this technique, a laser beam is directed through a vapor which contains a chemically reactive species. The energy of the laser beam activates the chemical reaction or decomposition of the reactive species, causing the formation of a reaction product. If the conditions are proper, the reaction product deposits upon the surface of interest.
The deposition of coatings or layers by this approach is typically accomplished within a deposition chamber. The target surface is placed into the deposition chamber, which is partially evacuated prior to commencing the deposition. Partial evacuation is usually required because the reaction product is likely to recombine prior to deposition if the ambient pressure is too high.
Although the general approach of laser-induced deposition has great potential, process limitations have prevented the full attainment of that potential. The need to place the surface or part that is to be coated into a vacuum chamber, and to pump down the vacuum chamber, slow the production rate. Moreover, the vacuum chamber must be sufficiently large to accommodate the part whose surface is to be coated, effectively limiting the size of the coated part in many practical situations. Moreover, it has been observed that the rate of deposition from a reactive gas using this approach tends to be slow, further limiting the production rate and efficiency of apparatus utilization.
There is a need for an improved approach to depositing coatings, layers, and films using laser-induced deposition techniques. The present invention fulfills this need, and further provides related advantages.